Fun fact - look at the Hat of Disguise; it specifically states it is attuned and the spell ends if the hat is removed. The Helm has neither of those restrictions… and it’s ’at will’ casting (for 1hour duration with no concentration). You can put it on, cast the spell, and then pass it to the next member of your party. Pass it around the group until you all have Comprehend Languages up and running. Very handy for mixed language negotiations with different nationalities or factions. 

Green goblin

Not exactly a fashion statement.

If you're getting that specific, then realize it doesn't say you can speak the other language. You'll have to hand it to they adversary your speaking with too.